Obesity is considered a long-term metabolic disease. There are several serious medical sequelae related to obesity. There are over 1 billion overweight individuals worldwide with 100 million clinically obese. The increasing health care costs of treating obesity related diseases in the US alone are estimated at over $100 billion annually. Current methods for treating obesity include behavioral modification, diet, surgery (gastroplasty), administering pharmaceutical agents that block appetite stimulating signals or absorption of nutrients (fat), and administering agents that increase thermogenesis or fat metabolism. Some of these methods have disadvantages in that they rely on patient resolve, are invasive, or have unwanted side effects. An understanding of the mechanisms by which obesity is regulated may provide important therapeutic information.
Obesity is frequently associated with insulin resistance and together constitutes risk factors for later development of type 2 diabetes and cardiovascular diseases. Insulin resistance occurs well before development of type 2 diabetes, and insulin is overproduced to compensate for the insulin resistance and to maintain normal glucose levels. Type 2 diabetes ensues, as the pancreas can no longer produce enough insulin to maintain normal glucose levels. Early stages of type 2 diabetes are associated with elevated levels of insulin but as the disease progresses the pancreas may fail to produce insulin, resulting in increased blood glucose levels. Diabetes is a significant risk factor for both heart disease and stroke and is the leading cause of blindness and end-stage renal failure.
Diabetes is a disorder characterized by hyperglycemia due to deficient insulin action that may result from reduced insulin production or insulin resistance or both. Diabetes mellitus is a polygenic disorder affecting a significant portion of the people in the world. It is divided into two types. In type I diabetes, or insulin-dependent diabetes mellitus (IDDM), patients produce little or no insulin, the hormone that regulates glucose utilization. In type 2 diabetes, or noninsulin-dependent diabetes mellitus (NIDDM), patients often have plasma insulin levels that are the same compared to nondiabetic humans; however, these patients have developed a resistance to the insulin stimulating effect of glucose and lipid metabolism in the main insulin-sensitive tissues, i.e., muscle, liver and adipose tissues, and the plasma insulin levels are insufficient to overcome the pronounced insulin resistance. Additionally, glucotoxicity, which results from long-term hyperglycemia, induces tissue-dependent insulin resistance (Nawano et al., Am. J. Physiol. Endocrinol. Metab., 278, E535-543) exacerbating the disease. Type 2 diabetes accounts for over 90% of all diabetes cases. It is a metabolic disorder characterized by hyperglycemia leading to secondary complications such as neuropathy, nephropathy, retinopathy, hypertriglyceridemia, obesity, and other cardiovascular diseases generally referred to as metabolic syndrome.
Metabolic syndrome is a combination of medical disorders that increase one's risk for cardiovascular disease and diabetes. The symptoms, including high blood pressure, high triglycerides, decreased HDL and obesity, tend to appear together in some individuals. Metabolic syndrome is known under various other names, such as (metabolic) syndrome X, insulin resistance syndrome or Reaven's syndrome.
Diabetes and obesity (sometimes now collectively referred to as “diabesity”) are interrelated in that obesity is known to exacerbate the pathology of diabetes and greater than 60% of diabetics are obese. Most human obesity is associated with insulin resistance and leptin resistance. In fact, it has been suggested that obesity may have an even greater impact on insulin action than diabetes itself (Sindelka et al., Physiol Res., 51, 85-91). Additionally, several compounds on the market for the treatment of diabetes are known to induce weight gain, a very undesirable side effect to the treatment of this disease. Therefore, a compound that has the potential to treat both diabetes and obesity would provide a significant improvement over current treatments.
Fibroblast growth factor receptor 4 (also known as FGF receptor-4, TKF; tyrosine kinase related to fibroblast growth factor receptor; hydroxyaryl-protein kinase; tyrosylprotein kinase; Fgfr4; FGFR-4; FGFR4; CD334, FGFR4_HUMAN and JTK2) has high affinity for the acidic and/or basic fibroblast growth factors. (Armstrong et al., Genes Chromosomes Cancer, 4, 94-98).
Although FGFRs generally have been shown to have wide distribution throughout the body, to date, FGFR4 has only been found in a few tissues. Among a wide variety of cells and tissues tested, including human lymphocytes and macrophages, FGFR4 was found to be expressed in the lung and in some tumors of lung origin as well as in malignancies not derived from lung tissues. (Holtrich et al., Proc. Nat. Acad. Sci., 88, 10411-10415). FGFR4 has also been found to be expressed in the liver and in adipose tissues. (Patel et al., JCEM, 90(2), 1226-1232). FGFR4 has also been found to be expressed in certain carcinoma cell lines. (Bane et al., Cancer Res., 62, 840-847).
Additionally, FGFR4 has been shown to play a role in systemic lipid and glucose homeostasis. FGFR4-deficient mice on a normal diet exhibited features of metabolic syndrome that include increase mass of insulin resistance, in addition to hypercholesterolemia. FGFR4 deficiency was shown to alleviate high-fat diet-induced fatty liver in a certain obese mouse model, which is also a correlate of metabolic syndrome. Restoration of FGFR4, specifically in hepatocytes of FGFR4 deficient mice, decrease plasma lipid level and restored the high fat diet-induced fatty liver but failed to restore glucose tolerance and sensitivity to insulin. (Huang et al., Diabetes, 56, 2501-2510).
Antisense inhibition of FGFR4 provides a unique advantage over traditional small molecule inhibitors in that antisense inhibitors do not rely on competitive binding of the compound to the protein and inhibit activity directly by reducing the expression of FGFR4. A representative United States patent that teaches FGFR4 antisense inhibitors includes U.S. Pat. Publication No. US2010/0292140, of which is herein incorporated by reference in its entirety. Antisense technology is emerging as an effective means for reducing the expression of certain gene products and may therefore prove to be uniquely useful in a number of therapeutic, diagnostic, and research applications for the modulation of FGFR4.
There is a currently a lack of acceptable options for treating metabolic disorders. It is therefore an object herein to provide compounds and methods for the treatment of such diseases and disorder. This invention relates to the discovery of novel, highly potent inhibitors of FGFR4 gene expression.
All documents, or portions of documents, cited in this application, including, but not limited to, patents, patent applications, articles, books, and treatises, are hereby expressly incorporated-by-reference for the portions of the document discussed herein, as well as in their entirety.